The present invention relates to a syringe for an infusion pump. More particularly, the present invention relates to a syringe that fits inside a small infusion pump, such as infusion pumps used by diabetics to inject insulin or other medication at controlled rates.
The present invention is capable of use with the infusion pump having a sealed drive mechanism and improved method of occlusion detection for determining the presence of obstructions in the infusion path set forth in co-pending application Ser. No. 09/335,999, which is incorporated herein by reference.
Briefly stated, the present invention is a syringe for use with an infusion pump. The infusion pump has a cavity for receiving the syringe. The syringe comprises a syringe body, a plunger and an end cap. The syringe body comprises a tube that is open at a first end and transitions to a passage at a second end and a connector extending from the passage, the connector for attachment to an infusion set or tubing. The plunger is slidably mounted inside the tube and comprises a plunger tip and a plunger rod. The plunger tip has a front face that is complementarily received by the second end of the tube and a rear face, the plunger tip forming an interference fit with the tube. The plunger rod has a first end attached to the plunger tip and a second end extending outside the first end of the tube. The plunger rod has a cross-sectional shape that is complementarily received by the cavity of the infusion pump when inserted in only one direction. The end cap is attached to the first end of the tube and has an opening that is shaped to complementarily receive the plunger rod.
In another aspect, the present invention is a syringe for use with an infusion pump. The infusion pump has a cavity for receiving the syringe. The syringe comprises a syringe body, various transitions, a plunger and an end cap. The syringe body comprises a tube that is open at a first end and transitions to a passage at a second end and a connector extending from the passage, the connector for attachment to an infusion set or tubing. The transition from the tube to the second end of the tube comprises rounded corners. The transition from the second end of the tube to the passage also comprises rounded corners. The plunger is slidably mounted inside the tube and comprises a plunger tip and a plunger rod. The plunger tip has a front face that is complementarily received by the second end of the tube and a rear face, the plunger tip forming an interference fit with the tube. The plunger rod has a first end attached to the plunger tip and a second end extending outside the first end of the tube. The plunger rod has a cross-sectional shape that is complementarily received by the cavity of the infusion pump when inserted in only one direction. The end cap is attached to the first end of the tube and has an opening that is shaped to complementarily receive the plunger rod.